Process and materials for coiling z-filter media; and/or closing flutes of filter media; and, products

Abstract

Approaches to providing z-filter media constructions are provided. Preferred corrugated media, filter constructions having such corrugated media, and filter systems using such filter constructions are provided. Also, preferred methods of forming filter constructions are provided.

What is claimed is: 
     
       1. A method of preparing a filter construction for use in an air cleaner; the method comprising steps of:
 (a) providing a filter media construction comprising a fluted filter media sheet secured to a facing sheet of filter media with a first seal therebetween against a first side of the facing sheet; 
 (b) forming a generally circular coiled configuration by coiling the filter media combination around itself with the facing sheet directed to the outside of the coiled configuration and with a second sealant strip, during the coiling, positioned between the fluted filter media sheet and a second side of the facing sheet;
 (i) the step of forming a coiled configuration comprising providing a resulting generally circular coiled configuration in the form of a coreless coil having a central open space; 
 
 (c) distorting the generally circular coiled configuration having a central aperture to a media construction having a non-circular shape;
 (i) the step of distorting including closing the central open space with sealing of the fluted filter media to itself; and, 
 
 (d) positioning a housing seal on the media construction. 
 
     
     
       2. A method according to  claim 1  wherein:
 (a) the step of forming a generally circular coiled configuration comprises coiling the filter media on a hub and then removing a resulting generally circular coiled configuration from the hub to provide the coreless coil having a central open space. 
 
     
     
       3. A method according to  claim 2  wherein:
 (a) the first seal between the fluted media sheet and the facing sheet comprises a sealant strip. 
 
     
     
       4. A method according to  claim 3  wherein:
 (a) the sealant strip positioned between the fluted filter media and the second side of the facing sheet is a polyurethane composition that increases in volume during cure. 
 
     
     
       5. A method according to  claim 4  wherein:
 (a) the sealant strip positioned between the fluted filter media and the second side of the facing sheet is a polyurethane composition that increases in volume by at least 40% during cure. 
 
     
     
       6. A method according to  claim 1  wherein:
 (a) the step of positioning a housing seal comprises positioning a framework on the filter media construction and providing a housing seal on the framework. 
 
     
     
       7. A method according to  claim 1  wherein:
 (a) said step of distorting comprises forming at least six interdigitized flutes along a center strip of the z-filter media construction, in the region of the second sealant strip. 
 
     
     
       8. A method according to  claim 1  wherein:
 (a) the step of distorting comprises distorting such that the second sealant strip forms the central seal in the resulting construction with no center core. 
 
     
     
       9. A method according to  claim 1  including:
 (a) adding polyurethane to a space inside of the coreless coil to form the media construction. 
 
     
     
       10. A method according to  claim 1  including:
 (a) providing a foamed polyurethane housing seal gasket secured to the outer surface of the media construction. 
 
     
     
       11. A method according to  claim 1  wherein:
 (a) the facing sheet is a non-corrugated sheet. 
 
     
     
       12. A method according to  claim 1  including a step of:
 (a) applying the second sealant strip to the fluted sheet before coiling with:
 (i) a selected amount of sealant applied a first distance from a nearest edge of the filter media construction at a first location of the filter media construction adjacent a lead edge of the strip; 
 (ii) a selected amount of sealant applied to a second distance from the nearest edge of the filter media construction in a second location of the filter media construction following the first portion, the first distance being further than the second distance; and, 
 (iii) a selected amount of sealant applied a location of the filter media construction near a tail end and at a location further from a closest edge than the sealant on the second portion of the filter media construction. 
 
 
     
     
       13. A method according to  claim 1  including a step of:
 (a) sealing a tail end of the media along its length by a sealant. 
 
     
     
       14. A method according to  claim 13  including a step of:
 (a) sealing a tail end of the media along its length by a hot melt sealant. 
 
     
     
       15. A method according to  claim 14  wherein:
 (a) the tail end of the media is positioned along a straight side of the media construction. 
 
     
     
       16. A method according to  claim 1  wherein:
 (a) the step of distorting comprises distorting to a shape having two generally parallel sides joined at the ends by curved portions. 
 
     
     
       17. A method according to  claim 16  wherein:
 (a) the step of distorting comprises forming an inner sealant strip in a center of the resulting media construction that is at least 12 cm long. 
 
     
     
       18. A method of according to  claim 1  wherein:
 (a) the step of forming a generally circular coiled configuration comprises coiling the filter media construction at least 10 times around. 
 
     
     
       19. A method according to  claim 18  wherein:
 (a) the step of forming a coiled configuration comprises providing a generally circular coiled configuration having an outside perimeter of at least 60 cm. 
 
     
     
       20. A method according to  claim 1  wherein:
 (a) the step of forming a coiled configuration comprises providing a generally circular coiled configuration having an outside perimeter of at least 60 cm. 
 
     
     
       21. A method of preparing a filter construction for use in an air cleaner; the method comprising steps of:
 (a) providing a filter media construction comprising a fluted filter media sheet secured to a facing sheet of filter media with a first seal therebetween against a first side of the facing sheet; 
 (b) forming a generally circular coiled configuration by coiling the filter media combination with the facing sheet directed to the outside of the coiled configuration and with a second sealant strip, during the coiling, positioned between the fluted filter media sheet and a second side of the facing sheet;
 (i) the step of forming a coiled configuration comprising providing a resulting generally circular coiled configuration in the form of a coil having a central open space; 
 
 (c) distorting the generally circular coiled configuration having a central aperture to a media construction having a non-circular shape;
 (i) the step of distorting including closing the central open space with sealing of the fluted filter media to itself; and, 
 
 (d) positioning a housing seal on the media construction.